1. Field of the Invention
This invention relates to hair spray resin compositions, and, more particularly, to fixative polymers for use in hydrocarbon tolerant aerosol formulations which exhibit advantageous small spray particle size, short tack and drying time, and hydrolytic stability, which are advantageous performance characteristics on hair.
2. Description of the Prior Art
Effective hair spray formulations and film-forming resins must meet a rigid set of requirements. Specifically, the film-forming resins should remain non-tacky in a humid environment but be easily removed using soap solutions such as shampoos. The film should have high hair cohesivity and possess sufficient strength and elasticity so as to avoid dusting or flaking when the hair is subjected to combing or brushing tresses, and remain clear, transparent and glossy on aging. The film-forming resin should have a viscosity range which permits spraying without nozzle clogging, and should show little or no tendency to interact with perfumes or other optional components typically utilized in a hair spray formulation. The resin should also be readily soluble in various solvents while exhibiting good compatibility with conventional propellants such as hydrocarbons, dimethyl ether, or mixtures thereof.
Many polymeric systems have been developed in an attempt to meet these stringent requirements. Among these are polyvinylpyrrolidone and copolymers of N-vinylpyrrolidone with vinyl acetate. However, these copolymers do not exhibit the desired degree of holding under high humidity conditions. Methyl vinyl ether/maleic acid half ester copolymers also have been used in hair sprays but these must be of a relatively high molecular weight to achieve adequate holding. Vinyl acetate polymers having 15 to 35 percent of their acetate groups converted to hydroxyl groups have been proposed for increased solubility in carbon dioxide propellant systems. However such increased solubility is achieved at the cost of lower holding power. While each of the above resins meets at least some of the above cited requirements, none exhibit all of these characteristics to a satisfactory degree.
Chuang, in U.S. Pat. Nos. 4,689,379; 4,961,921; 5,196,495 and 5,275,811; described improved hair fixative resins which were terpolymer resins of random or alternating structure having (1) a vinyl ester, (2) a water-insoluble or water-miscible alkyl maleate half-ester and (3) an acrylate or methacrylate ester of a saturated hydroxylated bicyclic hydrocarbon, or an N-substituted acrylamide. The resin was prepared in the form of beads or microspheres by suspension polymerization to provide a suitably high molecular weight for improved hair holding under humid conditions.
Other related hair spray compositions in this field include U.S. Pat. Nos. 3,145,147; 4,223,009; 4,842,852; 4,859,455; 4,923,695 and 4,933,170.
Accordingly, it is an object of the present invention to provide a hydrolytically stable hydrocarbon tolerant hair spray resin composition which can develop fine spray patterns, and which exhibits prolonged curl retention under humid conditions, short tack and drying times, good holding power, ease of removability and resistance to polymer build-up.
These and other objects and features of the invention will be made apparent from the following more particular description thereof.